What is Zero-dark-buffalo-hour?
A time to be ready that is considered too early in the morning. Usually, it is a time between 02:00 and 05:00 a.m.
Director: Tomorrow's schedule begins at 05:00 a.m., so be ready by 04:30 a.m.
Employee (under his breath): Oh crap! Another Zero-Dark-Buffalo-Hour timing!
Employee One: What time do we have to be ready?
Employee Two: Zero-Dark-Buffalo-Hour
Employee One: Shit! I wanted to sleep in!